Radiographic Study of Developmental Alteration in Tooth Number Among Children in IIUM Dental Clinic

Background: The aim of this research was to determine the prevalence, distribution and association of developmental alteration in tooth number with gender, location, and presence of delayed eruption of tooth among children who attended to Student's polyclinic of IIUM Kuantan, Malaysia. Methods: A cross sectional study on total 727 Orthopanthomograms (OPGs) of 3-17 years old children from April 2009 to July 2012. OPGs with presence of alteration number were scrutinized to find out the prevalence, distribution and association. The data was analyzed comparing gender, location and presence of delayed eruption and tested using Chi-square test. Results: Out of 727 OPGs, 71 OPGs showed developmental alteration in tooth number. The prevalence was 98/1000 OPGs within 3 years. Among those 71 OPGs, the gender differences were: males (49.3%) and females (50.7%). Locations were found in maxilla (45.1%), mandible (40.8%) and both (14.0%). The finding of delayed eruption was (7.0%). There were significant differences between alteration in tooth number with location as (p<0.05) while there were no significant differences with gender and delayed eruption as (p>0.05). Conclusions: This study showed that hyperdontia was considerably lower than hypodontia. There was association between alteration in tooth number with location, but no association with gender and delayed eruption

Genome-wide association study of primary tooth eruption identifies pleiotropic loci associated with height and craniofacial distances

Twin and family studies indicate that the timing of primary tooth eruption is highly heritable, with estimates typically exceeding 80%. To identify variants involved in primary tooth eruption we performed a population based genome-wide association study of ‘age at first tooth’ and ‘number of teeth’ using 5998 and 6609 individuals respectively from the Avon Longitudinal Study of Parents and Children (ALSPAC) and 5403 individuals from the 1966 Northern Finland Birth Cohort (NFBC1966). We tested 2,446,724 SNPs imputed in both studies. Analyses were controlled for the effect of gestational age, sex and age of measurement. Results from the two studies were combined using fixed effects inverse variance meta-analysis. We identified a total of fifteen independent loci, with ten loci reaching genome-wide significance (p<5x10−8) for ‘age at first tooth’ and eleven loci for ‘number of teeth’. Together these associations explain 6.06% of the variation in ‘age of first tooth’ and 4.76% of the variation in ‘number of teeth’. The identified loci included eight previously unidentified loci, some containing genes known to play a role in tooth and other developmental pathways, including a SNP in the protein-coding region of BMP4 (rs17563, P= 9.080x10−17). Three of these loci, containing the genes HMGA2, AJUBA and ADK, also showed evidence of association with craniofacial distances, particularly those indexing facial width. Our results suggest that the genome-wide association approach is a powerful strategy for detecting variants involved in tooth eruption, and potentially craniofacial growth and more generally organ development

Mesiodens preventing eruption of a permanent central incisor

A maxillary midline supernumerary tooth is the most common type of supernumerary tooth. We present a case of a mesiodens, preventing eruption of a permanent central incisor. The aetiology, diagnosis and the effect of these developmental anomalies upon the dentition are discussed.peer-reviewe

Whole exome sequencing in an Italian family with isolated maxillary canine agenesis and canine eruption anomalies

Objective: The aim of this study was the clinical and molecular characterization of a family segregating a trait consisting of a phenotype specifically involving the maxillary canines, including agenesis, impaction and ectopic eruption, characterized by incomplete penetrance and variable expressivity. Design: Clinical standardized assessment of 14 family members and a whole-exome sequencing (WES) of three affected subjects were performed. WES data analyses (sequence alignment, variant calling, annotation and prioritization) were carried out using an in-house implemented pipeline. Variant filtering retained coding and splice-site high quality private and rare variants. Variant prioritization was performed taking into account both the disruptive impact and the biological relevance of individual variants and genes. Sanger sequencing was performed to validate the variants of interest and to carry out segregation analysis. Results: Prioritization of variants “by function” allowed the identification of multiple variants contributing to the trait, including two concomitant heterozygous variants in EDARADD (c.308C&gt;T, p.Ser103Phe) and COL5A1 (c.1588G&gt;A, p.Gly530Ser), specifically associated with a more severe phenotype (i.e. canine agenesis). Differently, heterozygous variants in genes encoding proteins with a role in the WNT pathway were shared by subjects showing a phenotype of impacted/ectopic erupted canines. Conclusions: This study characterized the genetic contribution underlying a complex trait consisting of isolated canine anomalies in a medium-sized family, highlighting the role of WNT and EDA cell signaling pathways in tooth development

Open versus closed surgical exposure of canine teeth that are displaced in the roof of the mouth

Background: Palatal canines are upper permanent canine (eye) teeth that have become displaced in the roof of the mouth. They are a frequently occurring anomaly, present in 2% to 3% of the population. Management of this problem is both time consuming and expensive and involves surgical exposure (uncovering) followed by fixed braces for 2 to 3 years to bring the canine into alignment within the dental arch. Two techniques for exposing palatal canines are routinely used in the UK: one method (the closed technique) involves orthodontically moving the canine into its correct position beneath the palatal mucosa and the second method (the open technique) involves orthodontically moving the canine into its correct position above the palatal mucosa. Objectives: To establish if clinical, patient centred and economic outcomes are different according to whether an ’open’ or ’closed’ technique is employed for uncovering palatal canines. Search strategy: MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL) and the Cochrane Oral Health Group’s Trials Register were searched (to 29th February 2008). There were no restrictions with regard to publication status or language. Selection criteria: Patients receiving surgical treatment to correct upper palatally impacted canines.Therewas no restriction for age, presenting malocclusion or the type of active orthodontic treatment undertaken. Unilateral and bilaterally displaced canines were included. Trials including participants with craniofacial deformity/syndrome were excluded. Data collection and analysis: Two review authors independently and in duplicate assessed studies for inclusion. The Cochrane Collaboration statistical guidelines were to be followed for data synthesis

A Methodology for Three-Dimensional Quantification of Anterior Tooth Width

The use of cone-beam computed tomography (CBCT) technology has been shown to be more accurate in measuring individual incisor tooth widths than the use of wax exemplars. There were fewer differences by investigators using CBCT than others using an F-test in a mixed model of the measurement differences of investigators, wax type, and which tooth was measured. In addition, the frequency of outliers was less in the CBCT method (a total of 5) as compared to the two-dimensional measurements in ether Aluwax (a total of 8) or Coprwax (a total of 12). Both results indicate that CBCT measurements accounted more precisely for tooth width and level of eruption

A review of the eruption of primary teeth.

Introduction Eruption of deciduous teeth remains a rather sophisticated process. This paper gives a general overview of the process and explores on its implications. Overview Eruption of deciduous teeth may be divided into pre-eruptive tooth movement, eruptive tooth movement and post-occlusal tooth movement. Emergence of deciduous teeth is usually accompanied by teething symptoms. Mechanisms for eruption are still not entirely apparent. Proposed mechanisms included root elongation, hydrostatic pressure, periodontal ligament traction, bone remodeling and genetic pre-programming / cellular-molecular determinants. Discussion and Conclusion Understanding of the eruption of deciduous teeth made possible age estimation for children, shed light on management of teething issues and likely point towards a treatment philosophy of minimal intervention with definite building blocks of close observation and monitoring.published_or_final_versio

The acrocallosal syndrome: A case report and literature survey

Acrocallosal syndrome (ACS) is a rare, genetically transmitted disorder characterized by facial deformities. These include a large forehead, large anterior fontanelle, broad nasal bridge with increased intercanthal distance, partial or complete agenesis of the corpus callosum, polysyndactyly, polydactyly, and mental retardation. Limited information concerning the dental development and treatment has been published. In addition to the classic facial deformities aforementioned, the other most commonly reported oral findings are: short philtrum/upper lip (30%); high-arched palate (30%); cleft lip/palate (20%); micro/retrognathia (13%); open mouth (15%); thin lips (11%); and 1 report of over-retained primary teeth. Seizure disorders are also a common finding due to the neuroanatomical deformities associated with this disorder. The purpose of this report was to describe the case of a 7-year-old male child with acrocallosal syndrome who presented with a cleft lip and palate, hydrocephalus, a seizure disorder, and delayed exfoliation of his primary dentition and was observed for 4 years. A review is conducted to present the pertinent medical literature concerning the oral findings associated with ACS. Dental management of this case and possible contributing factors of delayed exfoliation/permanent tooth eruption are also discussed

Congenital Adrenal Hyperplasia: A Case Report with Premature Teeth Exfoliation and Bone Resorption

Congenital adrenal hyperplasia (CAH) is an inherited autosomal recessive disorder characterized by insufficient production of cortisol. The aim of this case report was to present a child with CAH, premature exfoliation of primary teeth and accelerated eruption of his permanent teeth related to bone resorption. A 4.5-year-old Caucasian boy with CAH and long-term administration of glucocorticoids was referred for dental restoration. Clinical examination revealed primary molars with worn stainless steel crowns, severe attrition of the upper canines, and absence of the upper incisors. Before the completion of treatment, abnormal mobility of the first upper primary molars and the lower incisors was detected, and a few days later the teeth exfoliated prematurely. Histologic examination revealed normal tooth structure. Alkaline phosphatase and blood cells values were normal. Eruption of the permanent dentition was also accelerated. Tooth mobility was noticed in the permanent teeth as soon as they erupted, along with bone destruction. Examination revealed an elevated level of receptor activator of nuclear factor-kB ligand and lower-than-normal osteoprotegerin and vitamin D levels. The patient was treated with vitamin D supplements, and his teeth have been stable ever since. CAH is a serious chronic disorder appearing in children with accelerated dental development and possibly premature loss of primary teeth